Screening apparatus



Y Jan. z5, i927, 1,615,559

M. B. TARK SCREENING APPARATUS Filed Sept. 14, 1923 OODOOOOOOOOOOBOBOUOOOUOOOOOOQODOC 00000006000000000000000 Patented Jan. 25, 1927.'

MARCUS n. TARN, ,or PHILADELPHIA, rENNsYLvANIA.

SCREENING APPARATUS.

- Application tiled September 14, 1928. Serial No. 662,699.

The present invention relates in general to a screening medium orapparatus forrempving objects from a liquid body of that t pe in whichthe medium "comprises a plura ity of bars or wires stretched across thepassageway of a frame adapted to be placed in the path of a movingfluid.

An important object of the invention is to so position the openings inwhich the elements of the screening medium are secured in the sidemembers of the frame that the frame .will not be weakened along anyparticular section due to loss of material in providing for saidopenings.

Aeature of the invention is to provide a bowing or 'supporting membersecured to the frame, the object of which is to prevent the bars orwires from moving sidewise and to keep them under tension after they areonce secured in the openings in the frame.

Another object is to provide a screening medium that may be constructedin small individual units for use as a single unit or secured togetherto form a larger medium, for exam le, a cylindrical screening mediumcompose of individual segmental units joined together.

Another object is to make the screening medium so that it can be readilytaken apart for changing or replacing certain elements thereof.V

Other features and objects will appear from a-detailed description ofthe invention which consists in the features of construction andcombinations ot parts hereinafter described and claimed. v

Referring to the drawings: c

Figure 1 is an end or axial view of one unit of a cylindrical or drumscreening apparatus and represents a segmental arcuate section from anapparatus composed of a plurality ot' such units secured together;

Figure 2 is a front elevational view of the unit showing the screeningmedium in its preferred form as a plurality ot' closely spaced bars orwires; y

Figure 3'is a vertical sectional view taken on the line of Figure 2; and

Figure 4 is a cross-sectional view taken on the line 4 4 ot' Figure 2,looking at the side of the spacing ri As shown in Figure 2, the frame ofthe screening apparatus is -composed of side members l and 2 andvertical supporting members 3 and 4, with intermediate verticalsupporting members 5 secured to the side members. In the preferred formof the invention, the entire frame is made of some suitable cast metaland therefore the fiance really constitutes a single casting. It isobvious, however, that the frame may be constructed of any suitablematerial which is capable of being machined and possessessuiiicientmechanical strength. Moreover, the frame as constructed maytake any preferred shape, such as a rectangle, a circle, or as shown, asection of segmental form, such section forming only a Fractional partof the entire screening medium.Y From an examination of the drawings, itwill be obvious that a number of such segmental sections are joinedtogether to constitute a large cylindrical screenin medium. Theinvention does not reside in the shape that the frame may assume, but isdirected principally to the elements constituting the screening mediumand the method of assembling the same.

The oppositely disposed side members 1 and 2 of the frame have in thematerial thereof rows of staggered openings or holes l, 1b, 2, 2", thatis, all of the openings in the a row of openings of both members arestaggered with respect to all of the openings in the b row of openings.Furthermore, the openings in the a row of one member and those in therow of the other member should lie on the same straight line connectingany one pair of such oppositely disposed openings. The object in soplacing the openings is to allow for a relatively close positioning ofthe screening elements without causing all of the openings to fall inthe same row and thereby produce an appreciable loss ot' material in theframe, which would tend to weaken the frame decidedly along one sectionthereof. If all of the openings in the a. and b rows were placed in onerow, the amount of material remaining between adjacent openings would beinsufficient to insure a strong frame member, since there would be amarked tendency to fracture the `frame along the section comprising allof the openings. By placing the openings as disclosed, the screeningelements may still be arranged in close proximity to one another withoutdepriving the frame ot' any ot its strength along a particular sectionand the material remaining between adja- 'ceut openings in a particularrow is greatly increased. For reducing replacement costs and forstructural reasons it is also desirable to maintain the distancesbetween the 1IL and 2b openings and the 1b and 2a openings the same.This spacing of the rows of openings should be followed consistently,regardless of the particular configuration that the frame may assume.

In the frame shown in the drawings, the openings constitute holes whichare drilled through the side members 1 and 2, each member having a setof openings extending in a plane parallel to the set of openings 1n theopposite side member, one opening of each set extending parallel and inthe same direction with a corresponding opening in the other set andconstituting a pair of openings. This probably represents theconstruction wherein the reatest amount of material is lost and the.rame weakened to the greatest extent. The openings may only be cavitiessituated in the side members, but regardless of the form that they mayassume it will be readily seen that holes bored through the side memberswill produce an extreme case, considered structurally.

A supporting member or rib 6 is secured to the frame and extends acrossthe passageway of the frame intermediate the slde members 1 and 2. Thisrib is shown as being parallel to the members 1 and 2 and may be securedmechanically to the frame or cast integrally therewith. The latterconstruction is preferred and is therefore shown in the drawings. Thisrib is of a substantial thickness and projects from the frame at rightangles with the supporting members 3, 4 and 5 and to a considerabledistance beyond the surfaces of the side members 1 and 2. If a planeincluded the faces of the side members l and 2 it would not include theface of the rib 6, but would intercept the latter. The relative distancewhich the rib 6 projects beyond the faces of the side members 1 and 2may be clearly seen by referring to Figure 4.

The face 7 of the rib which is opposite to that face in contact with theframe has a plurality of equally spaced notches or slots 8 extendingtransversely thereof and to a substantial depth into said rib, the wallsof said notches or slots being parallel to each other. 'The number ofsuch notches or slots should correspond with the total number ofopenings in t e rows a and b and should be in substantial alignment withthe openings, that is, each of the notches lie in a line connecting thealternate opposite openings and the bottoms of the notches lie at apoint out of alignment with a line connecting the surfaces of the sideframe members in which the openings are located.

The screening medium comprises bars or wires 9 stretched across thepassageway in the frame and secured in the staggered openings. Each baror wire is cut to the same length and the opposite ends thereof are bentso as to extend substantially parallel to each other so that the endsmay project into the staggered openings. In forming the bars or wiresthe length between the bent portions thereof is slightly less than thedistance between any two opposite openings, that is, if a bar is to beinserted in the 1 and 2b o enings, the distances between the arallel entportions will be slightly less t an the distance between such openings.The same construction will appl to a bar or wire to be inserted in thelb an 2 openings. Therefore, the screening elements can all be madeaccording to the same dimensions since the distances between theopenings measured across the passageway are the same throughout.

In stretching the screening elements, the bent portions are forced intothe proper openings and the intermediate portion of the element willrest in the notch or slot corresponding to the openings. Since the rib 6projects above the side members 1 and 2, the effect that it willproduce, upon the screening element when placed in one of the notches onthe rib, will be one of bowing or flexing. Moreover, since the bentportions are forced or driven into the openings, the result will be thatthe elements are placed under tension and the bowing feature addssomewhat to the tension set up in the bar or wire. any possible sidewisemovement of the bars and consequently each element will fit in only onepair of openings and the corresponding notch. A ter the bent portions ofthe bars are resting in the openings they may be secured therein bymutilating the ends or any other means well known in the art.

From the above description it will be apparent that the screen presentsa very smooth even surface to the material to be filtered and theelements are not apt to be Veasily bent out of shape or damaged. The

screening medium also possesses the very desirable feature of ease inreplacing an element without in any way interfering with any otherelement, and since each element is of the same dimensions only one typeof bar or wire need be carried in stock.

I claim:

1. Screening apparatus comprising a frame, the two side members of whichhave a plurality of staggered openings therein, a bowing membersupported by said frame intermediate of said side members and having aplurality of notches therein, the walls of said notches being paralleland each of said notches lying in a line connecting said alternateopposite o enings, and a screening medium on said ame comprising aplurality of bars lying alongside of each other and resting in saidnotches and secured in said openings.

2. Screening apparatus comprising a The notches also serve t`o preventframe, the two side members of which have a plurality of staggeredopenings therein2 a bown member supported b said frame 1ntermeiate ofsaid slde mem rs and having a plurality of notches therein, the Walls ofsaid notches being parallel and each of said notches lying in alineconnecting said alternate opposite'openings, the bottoms of said notcheslying at a pomt out of alignment with a line connecting the surfaces ofsaid l0 side yframe members in which said openings are located, and ascreening medium on said frame comprising a plurallty of bars lyingalongside of each other and resting in said notches and secured in saidopenings. 15 In testimony whereofI I aix my signature.

MARCUS B. TARKr

